1. Field of the Invention
The present invention relates to an image data communication apparatus, and more particularly to an image communication apparatus having an image data memory.
2. Description of the Related Art
Facsimile apparatus is known which has an image memory for storing image data to be sent and received. The image memory is used for various purposes, such as: matching communication speed and printing speed or reading speed, maintaining communication data secret in private communications, temporarily storing image data for timer activated transmission, etc.
It is also well known, in computer technology, to provide parallel processing or multi-task processing to simultaneously process a plurality of tasks.
However, multi-task processing has not been applied to facsimile systems because of its cost and because of its inability to provide security in communication. For example, conventional apparatus cannot read originals (for subsequent timer activated transmission) while simultaneously printing an image which is being received.
The conventional apparatus can only accept timer activated transmission and can feed originals to a reading unit, but the conventional apparatus does not read the originals simultaneously.
Facsimile operations should be secure so that even if someone removes an original image from the apparatus, the apparatus should be able to do the above-described processing.
Multi-task processing, e.g., receiving and printing, or reading and storing require a plurality of high speed processors and an image memory having a large capacity.
For example, the receiving side of a facsimile apparatus has to guarantee a line receiving speed at least as great as the speed to which the sending side was set in a pre-transmission procedure. In other words, the receiving side can not delay the receiving process time. Accordingly, it has been necessary to provide a plurality of processors which process simultaneously; and consequently the cost of the apparatus becomes extremely large.
Alternatively, the sending side can be made to delay or change the sending speed but this must be done by adding fill bits having no valid data.